Today, President Obama redefined his administration's national security strategy. He delivered a wide-ranging speech that went from drone strikes to leak investigations to the prison at Guantanamo Bay. As NPR's Ari Shapiro reports, the president looks ahead to a day when the U.S. is no longer at war with al-Qaida.

ARI SHAPIRO, BYLINE: President Obama has never embraced the phrase global war on terror. But during his first term, he continued many of the Bush-era policies that grew out of that war. Today, he said, the situation is changing.

PRESIDENT BARACK OBAMA: This war, like all wars, must end. That's what history advises. That's what our democracy demands.

SHAPIRO: In an hour-long speech at the National Defense University, President Obama said the threat against the United States is not what it was after 9/11.

OBAMA: Today, the core of al-Qaida in Afghanistan and Pakistan is on the path to defeat. Their remaining operatives spend more time thinking about their own safety than plotting against us.

SHAPIRO: He said pulling back from this fight is a financial imperative and a moral one. One of this administration's preferred tools in this fight has been drones. Today, the president gave a more comprehensive defense of his drone war than ever before. He vehemently defended its legitimacy and also offered new restraint.

OBAMA: The same progress that gives us the technology to strike half a world away also demands the discipline to constrain that power or risk abusing it.

SHAPIRO: He revealed that Congress has been briefed on every drone strike. He transferred authority for the program from the CIA to the military, and he offered a set of rules limiting when drones can be used in the future.

OBAMA: Before any strike is taken, there must be near-certainty that no civilians will be killed or injured - the highest standard we can set.

SHAPIRO: The president also went into more detail than ever before about his reasons for the strike that killed an American, Anwar al-Awlaki. Obama has been heavily criticized for authorizing that killing without any judicial process. But the president said al-Awlaki was continuously trying to kill people.

OBAMA: When neither the United States nor our partners are in a position to capture him before he carries out a plot, his citizenship should no more serve as a shield than a sniper shooting down on an innocent crowd should be protected from a SWAT team.

SHAPIRO: Any future president can roll back the limits Obama announced today. So the president said he also wants more long-term changes, including to a law Congress passed just after 9/11 called the Authorization for the Use of Military Force. It gives the president the authority to kill terrorists anywhere in the world.

OBAMA: Unless we discipline our thinking, our definitions, our actions, we may be drawn into more wars we don't need to fight, or continue to grant presidents unbound powers more suited for traditional armed conflicts between nation states.

SHAPIRO: The president also talked about national security challenges here in the U.S., from homegrown terrorists to investigations of national security leaks. Obama said he has asked the attorney general to consult with media organizations to review the Justice Department guidelines on cases involving journalists and report back by mid-July.

OBAMA: Journalists should not be at legal risk for doing their jobs. Our focus must be on those who break the law.

SHAPIRO: Four years ago this week, President Obama gave a similar national security speech at the start of his presidency. There, he promised to close the Guantanamo Bay prison. Today, he tried to re-ignite that effort by lifting a ban on sending detainees back to Yemen and by appointing new people to work on transfers to third countries. Without the support of Congress, though, closing the prison may remain an impossible goal. Ari Shapiro, NPR News, Washington. Transcript provided by NPR, Copyright NPR.